This invention relates to a dynamic damping circuit for a horizontal deflection system of cathode ray tube display apparatus wherein a ringing potential due to sudden large variations in the white video signal is damped without undue power dissipation. Prior art type apparatus typically included a horizontal deflection system having a series connected horizontal deflection yoke and an "S" curve correction capacitor. A resistor was shunted across the "S" curve correction capacitor or coupled from the junction of the deflection yoke and "S" curve correction capacitor to a potential source B+ in order to damp the ringing potential developed thereacross whenever the load on the system abruptly changed due to the intermittent appearance of large video signals representative of white information.
In another known form of apparatus, an "S" curve correction capacitor of greatly increased value is employed. However, the "S" curve correction capacitor of increased magnitude merely serves as a coupling capacitor and has the disadvantage of not providing the desired "S" shaping whereupon the horizontal deflection is non-linear rather than linear.
Although the above-mentioned apparatus did provide dampening of the undesired variations in potential appearing across the "S" curve correction capacitor, it was found that such apparatus undesirably distorted the sawtooth current flowing in the deflection yoke. As a result, linearity of the deflection was deleteriously affected. Moreover, the above-described damping system undesirably required constant power application thereto which undesirably added to the power losses in the system.